Adaptive Bearing Sampling for a Constant-Time Surfacing A* path planning algorithm for gliders. - Enrique Fernández-Perdomo; Jorge Cabrera-Gámez 001; Daniel Hernández-Sosa; Josep Isern-Gonzalez; Antonio Carlos Domínguez-Brito; Víctor Prieto-Marañón; Antonio G. Ramos (ICRA, 2011)